1. Field of the Invention
The present invention relates to multi-functional markers for use on various products, particularly products which have one or more visually indistinguishable characteristics, for identifying and/or providing information about such products, and to processes and materials for making and using such markers.
2. Background of the Related Art
There is a demand for meat and agricultural products with specifically defined but visually undetectable characteristics. Examples include meat from range fed animals and organically grown vegetables. Premiums are paid for such products. These premiums have in turn created a demand for safe, reliable, easily read, and inexpensive markers on or in those products that can independently and securely verify their origin and provenance.
Other sources of demand for such markers include the following. The spread of bovine spongiform encephalopathy by contaminated animal protein supplements from the United Kingdom to Europe, the Middle East Asia, and North America has led consumers and regulators throughout the world to demand “agrotraceability,” a higher standard of proof of the origin and provenance of animal as well as human foods than is currently maintained in many parts of the world. Consumer diffidence about (and allergies to) food made from genetically modified organisms have extended the demand for traceability to all products intended for human and animal consumption, including nutritional supplements, vitamins, and flavorings. Fear of terrorism, domestic and foreign, has magnified this demand.
Parallel demand for safe, reliable, easily read, and inexpensive markers exists in other industries, such as the pharmaceutical, fragrance, and jewelry industries, where trade in premium products with attributes often indistinguishable by untutored sensory examination routinely encounters risks, such as passage across international borders, that make these products vulnerable to piracy. Careful packaging and continuous surveillance during transit and storage may partially address this demand, but neither totally excludes the possibility that the product within the package has been adulterated, either accidentally or deliberately.
The number of different products in each of the above-mentioned categories (for example, the number of different fields from which an agricultural product may originate) is in the millions; a marker of these products must be able to identify each one of these. At the same time, to prevent contamination of the enviroiument of the marked product, and subsequent contamination of other marked products by those residual markers, the markers must be designed to degrade under specified conditions after use. For example, markers of edible products must be digestible as well as edible.
The physical size of the markers must be sufficiently small such as not to change the specifications or the visual appearance of the marked products, and yet be sufficiently large so that the smallest informative dimension can be reproducibly identified. These requirements essentially constrain the dimensions of the markers to the sub-millimeter meter range. At this size, binary codes are distinctly more reliable, and less expensively read, than analog codes. The markers must be easily manipulable, so that they can be attached securely to the marked product in highly reproducible marker/product ratios, using methods that avoid or minimize obstacles to attachment such as electrostatic forces, surface tension, or air currents to which markers of this size could be susceptible.
Presently, no product in commerce meets all of these requirements.
Prior processes of marking food products and pharmaceuticals typically involve disposing a dye onto the surface of a product. For example, U.S. Pat. No. 6,299,374 discloses capillary feed marking instruments capable of dyeing edible colored marks directly on food substrates and medicaments. U.S. Pat. No. 6,068,981 discloses adding a substance to a medicament and detecting the ingested substance in the blood or other body parts following ingestion of the medicament by chemical, photoelectric or immunological methods. The number of such dyes or other substances easily detected and known to be safe, however, is small. Moreover, the use of synthetic molecules such as nuclcic acids, proteins or carbohydrates as markers of products that large numbers of people might ingest or use would require that each such molecule be rested for environmental as well as biologic safety and compatibility.
Small particulate markers have been proposed for tracking various products. For example, U.S. Pat. No. 3,861,886 describes a method of tagging bulk material with microparticles having properties different from the properties of the particles that make up the bulk material. U.S. Pat. Nos. 3,772,200 and 3,897,284 disclose refractory microparticles or polymeric microparticles containing low levels of elements such as manganese, cobalt, zinc, cadmiurn and tin. U.S. Pat. No. 4,053,433 discloses microparticles having an orderly sequence of visually distinguished colored segments U.S. Pat. No. 6,455,157 discloses the use of two or more different microparticles having several color layers forming a code, such as those described in U.S. Pat. No. 4,390,452, to mark products. All of these markers, however, are limited either by the materials required for their manufacture or by their limited adherence to or ability to maintain a uniform distribution among the marked objects.
U.S. Pat. No. 4,640,035 discloses markers made from transverse sections of an assembly of elongated elements. It is not possible, however, to distinguish one face of this marker from another, thereby limiting the amount of information it can store. In addition, this patent fails to disclose any commercially practical methods for manufacturing markers from these elongated elements.
Accordingly, there remains a need for a multi-functional product marker that is safe, reliable, easily-read and inexpensive marker for products that can independently and securely verify information about the marked product, such as its origin and provenance.
The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background.